A Mystery of Time
by BlinkingAngel
Summary: Ava Rallis has died under less-than-mysterious pretenses. For this case, however, Sherlock is interested more in her life than her death. I'm bad at descriptions, but VERY deduction filled and VERY wibbly-wobbly-timey-wimey. Sherlock/OC.
1. Case

John Watson found himself at the doorstep of 221B Baker St. unable to reach his key to the flat or properly knock on the door on account of the grocery bag in one hand and defense against the wet and gloomy London weather in the other. With some difficulty, he put down the bag, folded his dripping umbrella, fished the key out of his pocket, and opened the door, getting himself and the paper bag soaked in the process.

Inside, Sherlock was plucking at his violin, mercifully not yet playing it. He took notice of John's entry, but did not bother looking up.

"You know, you could at least try to do something," John said as he set down the bag again to hang up his soaked coat. "You've not moved for the past four days!"

dropping his violin to the floor, Sherlock whined, "Nothing's happening and I'm BORED!" in response. "Plus, Mrs. Hudson took my gun." He added with a forlorn glance at the wall riddled with holes.

Before John could make any further complaints, Sherlock's phone started ringing. He sprung up from his chair, glanced at it, and put it to his ear with a slight smile before the second ring.

"Lestrade, good. Have you got a case for me?… No, why… you really can't solve that yourse—… Well can't you just tell me now?… Fine, I'll be right there." With that, the now irritated genius was out the door with his coat and scarf, knowing that John would not be far behind.

"Where are we going?" Watson queried once they were in a cab.

Sherlock shot him a slightly confused (the diminutive amount of confusion that the genius detective was capable of) glance and quickly responded "Scotland Yard" before continuing to stare distractedly out the window.

"Why?"

"A girl died in a car accident. Lestrade won't tell me why it's important, but he wants me down there as soon as possible." Sherlock explained. Watson noticed the lingering hint of confusion in his voice, though his words confused John even more.

"An accident? Then what's the case?"

"My question exactly"

**A/N: **Sorry it's really short, but it's the first chapter in my first FanFic. I'll probably get another chapter up soon, but I don't have a definite plan yet. Please review, I love constructive criticism! Thanks for reading!


	2. Thought

**A/N: Just a quick note because I forgot last time: I do not own Sherlock or Doctor Who or any of their characters.**

Sherlock and John were greeted by Lestrade and lead to his desk upon arriving at the Yard. It was littered with stray papers, files, and an empty coffee mug.

"Thank you for coming, Sherlock" He said over his shoulder while sorting through some papers.

"Yes, now why exactly am I here? I know you lot usually need my help, but for murders and the like, not a car accident." Sherlock responded, overly stressing the word 'accident' and getting a disapproving glare from John.

Lestrade let out a sigh before pulling out an envelope. "Does the name 'Ava Raliss' ring any bells?" He asked as he handed the envelope over.

"No. Was that the woman in the crash?" Sherlock noted the fact that it was folded in half and slightly wrinkled. He deduced that it had been in a pocket or a purse, probably a purse because it was not creased tightly enough to be in a pocket for any length of time. It was there for a while, perhaps two weeks. He flipped the envelope around in his hands a few times before unfolding it to read the name on the front. _His_ name on the front. It was written in boxy and large, yet oddly neat print. A dark green pen. From the written name alone, he deduced that she (quite obviously 'she', he thought) was slightly boyish, but cared about how she presented herself, judging by the neatness. The whole process took him all of a second.

"You got this from her purse." He said simply before Lestrade got the chance to answer. "I don't know her. She wrote me a note?"

"Maybe she wanted your advice on something." Watson suggested, "between my blog and your website… you're getting noticed."

"No, this is at least two weeks old. She had it in her purse that whole time and never contacted me? Plus, she cared about how she presented herself, judging from the neat handwriting. She did not write in cursive, she printed my name. That means that it was informal. If she wanted to do business, she would want to look professional, therefore it would be more formal." Sherlock explained his deduction quickly while carefully putting the letter in his jacket pocket and smiling at the whispered "amazing" that escaped John's mouth.

"Anything else?" he asked while scanning over the mess of paperwork on Lestrade's desk. "You could have just come by the flat if this was all."

"We also found this at the crash site." He answered, handing over a small scrap of paper that looked like it was torn out of a note book. Drawn on it was a series of complicated circular shapes inside other circles all inter-connected. It was obviously not stamped or printed, but written in a number two pencil. It was almost as if they were words.

"What's this?" Sherlock asked, not taking his eyes off the shapes. He Memorizing their patterns. "It seems like another note of some sort, but not any kind of cipher that I've ever seen or heard of" he continued. "Whoever wrote this was rushed. I do not think that these are just drawings. It is too complicated and someone just doodling would not rush. This person was completely fluent in the cipher. Are you sure it wasn't just dropped? By the car? This person really wanted to say something, and to a specific person too, they wouldn't have left it in a dead woman's car."

Lestrade was obviously done with the conversation. "We didn't just find it on the street, it was shut in the window. We have no idea what it says, who put it there, or who it's for. We want you to find out for us. Good day Sherlock." With that, he grabbed his mug and walked away.

Sherlock stuffed the strange note into his pocket with the other and he and John walked off in the other direction.

*

The next three hours found Sherlock in his chair with three nicotine patches on his left arm and his fingers pressed together beneath his chin. He sat staring at the envelope and the hastily written note, both of which were propped up on a few books. Sherlock had not yet opened the letter. He simply stared at the two notes, the precise detail on each, from the paper they were written on, right down to the handwriting, if you could call the ciphered drawings 'handwriting'.

A half hour ago, he had noticed a small scribble indent in the corner of ciphered note from someone testing a pen on the back of the paper. When he turned it over, he saw the inverted indent with just a tiny hint of a dark green ink in the crevices. This confirmed one thing he did not consider at first: the notes were both written by that woman, Ava was it? She first wrote the letter to Sherlock, then later tried to use the same pen to write the cipher. Simple.

Of course, someone could simply have the same pen, but after studying the two notes for hours on end, Sherlock started to notice patterns in the writing and drawings. For example, the writer was obviously left handed, judging by the slight smear in the 'S' of his name and the fact that the pencil marks were slightly faded on the left side of the paper with the symbols.

But the one thing that nagged at him was that she wrote the note quickly, hand shaking. No, he thought, in a moving car. She had been found on an abandoned road and had crashed straight into a dilapidated building that was once a convenience store. She may have been writing as she drove. But what could be so important? Perhaps she knew she would die, but then why take the time in a moving car driving to your death to cipher a note and stick it in the window? Of course it could be suicide, but again, why write a suicide note in a cipher that no one could read?

It was then that Sherlock simply had to open the letter. He hadn't wanted to before, felt like he shouldn't, but he simply needed to know more about this Ava Raliss. He ripped open the envelope carefully, so as not to destroy his neatly written name on the front. He unfolded and smoothed the wrinkled paper. The letter was written in the same dark green pen and neat, boxy lettering. It read:

My Dear Sherlock,

First off let me say, my death was not a suicide or murder, simply an accident. A set point that could not be avoided. I know you will see this as quite dull, but it is, in fact, anything but. I'm not sure if we've met yet, and if not, I'm sorry. That fact will make this so much more confusing for you. Main point, I want you to come to my funeral. It will be very small, essentially just a burial, but I want you to be there. Details of when and where will probably be in the obituary soon. If you do choose to come, you will be able to sort all this out, but if you don't, none of this will ever have happened and you will never know why this strange woman wrote you a letter that you can remember but does not exist. Yes I know you and yes I knew I would die, but you have to find out how in time.

Godspeed, Mr. Holmes.

AvaRallis

Sherlock read and re-read the letter several times over. He was not quite sure what he had expected, but what had been written in that short letter was the largest surprise that the consulting detective was capable of experiencing.

Sherlock immediately threw the note on the table and sprung up from his chair. He strode over to John, who was quietly sitting on the sofa, reading and sipping a cup of tea. He snatched the newspaper out of his hands.

"Hey!" John protested, but Sherlock just held up a hand, signaling him to stop talking. He laid out the paper on the floor and threw pages here and there until he was left with only the one he wanted, the obituary. Sure enough, the article listed Ava Rallis near the top. It said that the funeral was to be held the following day at noon. He returned the one remaining page to John and started towards his chair once again.

"What was that about?" John asked, stopping Sherlock in his tracks.

Sherlock stayed where he was and answered without looking at John, "The letter." He said, just confusing the doctor more.

"The letter from the dead woman? What about it?" 

"I've been invited to her funeral." Sherlock replied quickly, getting slightly annoyed with all the questions. "_She_ invited me to her funeral. It's tomorrow at noon" 

"She-" John started to ask, but stopped mid-sentence, knowing that it was useless to keep asking how and why. Instead he asked "Will you go?"

Sherlock turned and replied with a smile, "Of course. Never could resist a good mystery."

Not another word was spoken the rest of the night. John collected his scattered newspaper and Sherlock returned to his 'thinking position' on the couch.

He continued to stare at the encoded note once again, trying to make sense of its complicated, mechanical-looking, circular shapes. The ease and lack of thought put into drawing in this strange language in the spur of the moment confused him. She was obviously fluent in it, so Sherlock had started to mentally refer to the code as a language. But Sherlock knew, if not knew of, every language on this planet. This led him, reluctantly, two possible explanations.

Number One: she made up the language and used it to communicate with the only other person that knew it, like a cipher. This seemed unlikely, considering how complicated the shapes were. He could not stop wondering why she would think to write a cipher in the last few moments of her life. Yet this conclusion seemed very likely, considering the alternative.

Sherlock did not even let himself consciously consider of the alternative because it was entirely impossible. His brain automatically denied the impossible.

Yes, he would definitely go to the funeral. He had to see this interesting woman that he could never meet.


	3. Funeral

**A/N: I'm really trying to improve on my chapter length now. I'm sorry for any mainly Doctor Who fans, I promise there will be more from now on.**

**Thank you to MeggyMooMoo for reviewing my last chapter! Reviews make me feel good.**

**As always, I hope you enjoy! I do not own Sherlock, Doctor Who, or any of their characters.  
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Sherlock stirred only twice the whole night. Once at about four in the morning to get John's laptop, and again at about seven to get his violin. He hadn't stopped trying to make sense of the circular shapes. He had searched for hours on John's laptop for something that even resembled the writing, but found nothing. Giving up on the internet to help him get answers, he went to get his violin.

John was enjoying what he thought would be a good night's sleep when he heard the loud tunes coming from the living room. His eyes snapped open with the first shrill note. He took a deep breath and dragged himself out of bed and into the living room where Sherlock continued to play viciously.

"Sherlock!" John yelled over the violin.

"Thinking, John!" Sherlock yelled back, continuing to play.

John walked over to Sherlock's chair. "Could you think a bit quieter please?" he said as he confiscated Sherlock's bow.

"Hey! Really John, it's seven in the morning, you should be awake anyway. Be grateful I didn't start earlier." He quietly sulked, returning to his thinking position and staring at the note.

"Have you eaten or slept at all in the last week? You're going to starve yourself."

Sherlock started, "Digesting-"

"'-Slows you down'" Watson interrupted, having heard the excuse too many times. "I know. But what work have you done in the last few days besides this? I'm at least making you a cup of tea and some biscuits." John said, halfheartedly concerned about his flat mate's health. He went into the kitchen, intending to put a kettle on. To his disgust, he found a couple fingers floating in some sort of thick liquid in their only kettle. A tiny voice in the back of his head wondered when Sherlock got the supplies for the creation and when he put it there. He quickly closed the lid of Sherlock's latest experiment. Feeling sick, John headed to the door.

"Where are you going?" Sherlock asked without looking away from his new obsession.

"Out. You may be able to live your entire life without leaving this room, but I can't." Watson grabbed his coat and umbrella just in case and left the flat. Being a former soldier and doctor, he was okay with a little gore, but it was a whole different story when it was localized in his kitchen. Just a walk, he thought. He'll be gone by noon.

Meanwhile, Sherlock found himself unable to look away from the symbols for any length of time. It drove him absolutely mad that he still hadn't decoded the message. He just couldn't make sense of the shapes. At some point, John returned from his walk and began to type away at his blog. Minutes turned into hours while he stared at the shapes. When Sherlock eventually glanced up at the clock sitting on the mantle, he was surprised that it was already nearly noon.

He sprung up from his chair and snatched up his long coat and his scarf. The stumped detective ran out the door without a word and skipped down the steps. He figured that he could walk the distance easily and started in the direction of the graveyard. Sherlock still saw the symbols floating in front of him as he walked. It was a very gloomy and overcast day, as was fitting for a burial.

He walked across the graveyard to where there was a deep grave dug in the ground. An open casket lay next to the hole, but there was not a soul around to see it. Sherlock thought this was strange, she should at least have some family or friends, but he continued to the grave, stopping only when he could fully see Ava Rallis inside.

She lay peacefully with hands folded over her chest. Sherlock couldn't help but analyze her. She did not have any scratches or evidence of an accident, meaning that she was killed by her chest cavity collapsing in the crash. She looked in her early-to-mid-thirties. She was thin, but healthy looking. She had thick, vibrantly red curls pulled into a long, neat ponytail over her left shoulder. He could tell that she never wore any makeup, judging by her blemish-free skin and lack of any wrinkles. Even without expression, she looked very unique. With the huge volume of her hair and exotic features, she could be compared to no one.

Sherlock heard a distant mechanical whirring coming from the direction of a single tree standing about three metres away from the grave. He initially dismissed it along with the other noises of London mid-day.

When the noise stopped with a hollow clunk, Sherlock spun around to find its source. He scanned the area once, twice, thrice, then finally saw it. For some reason, his attention skipped over the small area the first few times, which was strange considering his acute attention to detail.

The detective saw a man standing next to the short, thick tree. He wore a blue suit covered by a long brown trench coat that billowed behind him in the wind and red converse. His unruly brown hair stood up in every direction. The man stood stock still with his head tilted slightly up and hands shoved in the pockets of his long coat. He looked in his late thirties, but his eyes and posture told Sherlock that he was much older than he seemed. The man stared sadly at the face in the casket with eyes of a man that has seen death but was still surprised and stung by it. He did not take any notice of Sherlock standing next to the casket staring back at him.

Behind the man, almost concealed by the trunk and low hanging leaves of the tree, was what looked like a blue box. Through the leaves, Sherlock could make out a sign and a light about seven feet off the ground. Though he could not tell what the sign said, he could tell that the box, had he gotten a better look at it, would look like a wooden police telephone box from the nineteen-sixties. Sherlock was almost positive that he man and the box hadn't been there before. He wondered at it for a second, then put it in the back of his mind to be pondered later.

He looked away and decided, against his better instincts, to leave. He had stood at the grave for long enough and saw all he needed to see. Sherlock took one last look at the face of the mysterious, unique woman that had single handedly stumped the world's only consulting detective, and walked away.

He continued to think about the woman and tried to connect her to the letter and the odd language as he strode quickly down the street, not exactly in a hurry to get somewhere, but not in a hurry to stay. Sherlock dodged passersby as he made his way back to the flat, just one more street. He turned a sharp corner that led to Baker Street and in doing so, ran headlong into a woman walking equally as brisk and distracted in the opposite direction.

The collision sent the woman and Sherlock back in opposite directions, causing the contents of her shopping bag to spill all over the sidewalk. Sherlock quickly got up, intending to help her pick up her groceries. What he found was that her carton of milk was broken and spilling onto the concrete, her eggs were all smashed, and her box of tea bags had fallen into the street, only to be run over by a car. The woman rolled onto her feet and looked over her soiled groceries, now holding only the ripped, wet bag and the only salvaged item: a brush.

Sherlock, feeling guilty for causing the mess, looked up to apologize to her. All he saw was the back of her head as she surveyed the damage, but he felt something familiar as he gazed at the vibrant cascade of thick, red curls. The apology got caught in his throat when she turned, revealing her face for the first time. The pause lasted just a second.

"I am so sorry." He said slowly, looking over her features.

"It's fine," she said quietly. "only an accident."

"Well there must be something I can do." Sherlock quickly responded, desperate to talk to this woman. "Why don't you come over and I'll make you some tea. It's the least I can do, seeing as I've ruined yours." he gestured to the items scattered around them.

"That," she started hesitantly, wondering whether or not to trust this man. She decided he looked nice enough. "Would be wonderful." she finished with a smile.

"Great!" Sherlock exclaimed with a grin of his own. "I live just down on Baker Street. I'm Sherlock by the way. Sherlock Holmes." he added, extending a hand.

"Nice to meet you Mr. Holmes." she replied, taking his hand. "I'm Ava. Ava Rallis."

**A/N2: I know for sure where to go with this story now and should have another chapter soon. Please review and tell me what you think! Thank you all for reading!**


	4. Tea

**A/N: I do not own Sherlock, Doctor Who, or any of their characters.**

John was sitting on the sofa when he heard the front door being unlocked. He expected Sherlock to come in without a word, throw his coat and scarf to the ground, and continue to stare at that blasted paper. Instead, said detective walked into the flat holding Mrs. Hudson's kettle and talking over his shoulder to someone else walking up the steps. Confused, Watson put down the book he had been reading to see who his eccentric flat mate could have possibly brought home from a funeral.

"Make yourself at home; tea will be ready in a minute." Sherlock called over his shoulder as he walked into the kitchen and put on the kettle. A tall woman walked into the sitting room after him. She had huge, ginger curls spilling over her shoulders. She wore a professional looking, yet flattering purple suit with a watch chain hanging from her jacket and leading to her left pocket. She started to wander around, looking over the cluttered room with large, bright green eyes that complimented the fiery color of her hair.

"And who would this be, Sherlock?" Watson asked as the woman made her way to the mantle to examine the skull.

"This is Ava Rallis." Sherlock replied, walking back into the sitting room. "I ran into her on the street. Ava, this is my flat mate, Doctor Watson."

"John," he corrected, getting up to shake her hand. "Have we met before?" he asked, feeling like he had heard her name before.

"No, I don't think so, I think I just have one of those faces." she said, hesitantly shaking his hand. "It's nice to meet you though, John." Ava went back to looking around and soon disappeared into the kitchen.

John responded with only a nod and a confused look. "Really who is she?" he whispered to Sherlock, who had come to stand next to him.

"I told you, Ava Rallis." the other man whispered back.

"Well yes, but where have I heard that name before?" John was starting to get annoyed with the small answers.

"Perhaps you heard it from Lestrade." Sherlock replied simply with a smug grin. John thought about this. Meanwhile, Ava walked in, completely oblivious to the hushed conversation, holding a filthy jar.

"I found this in the microwave. Experiment?" she said, fine with the fact that Sherlock kept human eyes in the microwave. She walked back into the kitchen to return the eyes to the microwave before Sherlock could say anything. She continued to ramble as she went. "And I don't see why you needed to borrow your landlady's kettle, you've got a perfectly good one right- oh" she cut off, having opened the kettle of fingers. She came back into the sitting room, not looking at all fazed. "What's that then? Measuring elasticity of the skin after death? Clever."

Sherlock just stared, inwardly astonished but too prideful to show it. No one had ever even got over the fact that he used body parts for experiments, much less understood why. Just then, the finger-free kettle screamed. He walked briskly to the kitchen to finish the tea.

"You've got a nice place." Ava called after Sherlock. "A bit more clutter than my flat, but nice all the same."

Watson sighed and returned to his sofa. Having perused the whole front room, Ava helped herself to a seat across from the sofa and sat with legs crossed and back erect, still taking in the miscellaneous items scattered around. Sherlock joined them shortly with three cups of tea.

John then realized why the name 'Ava Rallis' seemed so familiar, yet so out of place. Ava Rallis was dead. As in body currently underground. So how could she be sitting in his flat, drinking tea? It's not like she had a terribly common name, and Sherlock usually wasn't polite enough to invite anyone over and then _personally_make them tea.

John shot a questioning glare at his flat mate as he settled into the chair he had left only to go to the funeral of the woman sitting in front of them.

"So tell us about yourself, Ava." John said, hoping to break the awkward silence that had fallen on the group.

"Well there's not much to tell." She said, suddenly shy. "I live here in London, I moved in two months ago from Chiswik and I've not found a job yet. I like challenges, real-world brain teasers you might say. Umm, I play flute sometimes when I'm thinking?" Sherlock noticed that she paused slightly on details about her past. John, on the other hand, could not get over how similar she and Sherlock seemed to be. "But I'm not all that interesting, let's talk about you." She said, quickly changing the subject and looking over to Sherlock. She uncrossed her legs and rested her elbows on her knees, staring at Sherlock. "You're a detective and a self-proclaimed genius. You also enjoy mysteries. You work with the police to solve murders because you are bored with anything else. You do not smoke, but use nicotine patches to help you think, and you occasionally play the violin, which your flat mate obviously does not appreciate." John let out a small "wow", realizing that he had just met the female equivalent of Sherlock.

Ava's simple monologue had left Sherlock awestruck. He had never doubted his own abilities, but to see someone else read him the way he did everyone else, left him speechless. John, though even more surprised, got quite a bit of amusement out of the expression on the detective's face. "Did I miss anything?" she asked with a smile.

Quickly composing his expression, he responded, "I'm a consulting detective. Only one in the world, I invented it."

Ava leaned back into the chair and covered her smile with a sip of tea. She scanned over the coffee table in front of her, eyes catching on the piece of paper with the symbols on it. Her expression instantly became blank and distant. She stared at it while unconsciously fingering the watch in her pocket. "What's that?" she asked quietly, not looking up.

Sherlock leapt up and snatched the note. "Nothing, just a case. Do you know what it says?" he asked with an almost excited and hopeful note in his voice. He stuffed it in his pocket.

"I don't…" she started, but trailed off still staring nostalgically at where the note had been. Her head snapped up as she was brought back to the present, eyes bright again as if nothing had happened. "But what I want to know," she said loudly as a way of changing the subject again, "is how you make such wonderful tea!"

The three sat together, chatting about Sherlock's cases and John's blog, for a few hours until Ava looked at the time, gasped, and said she had to leave.

"You should come over again sometime." Sherlock said as she headed to the door. He was not only intrigued by her intelligence and impossibility, but was also growing fond of her.

"I'd like that." She said. She walked out the door with one last, wholesome smile.

As soon as she was gone, John turned to his flat mate, who had gone back to thinking and staring at nothing. "Ava Rallis?" he asked, completely lost.

"Yes."

"Wasn't that the name of the woman in the crash?"

"Yes."

"So she has the same name?" he asked, hopefully.

"No, John. It's the same person."

"You're sure?"

"Yes. I saw her in the coffin."

"Yeah, okay. So she just got up and walked away? You are aware that that's _completely impossible_ right?"

Sherlock ruffled his mop of curly hair and looked up at John. "Of course it's impossible! I know that! The woman you just saw _is _Ava Rallis, but she's younger." The detective responded matter-of-factly. He sprung up and started pacing.

Watson was now completely flabbergasted. "Than the woman you saw dead? _How _is that possible? Are you suggesting time travel?"

Sherlock suddenly stopped and looked up at him, "I don't know! All I know are the facts. She was found dead in her car with the two notes, one to me talking to me like an old friend and one in another language. I go to her funeral, see her face. Then I find her on the street and she has no idea who I am or what the note says. Conclusion, it's in her future. I just don't know how!" He continued pacing with his head down.

"She wanted me to see her." He finally concluded after about ten minutes. "She wanted me to see her so I would recognize her on the street. I was meant to meet her. If her letter to me is in her future, then she remembers meeting me from her past and pieced it together backwards, or forwards and I'm doing it backwards. Either way, today's events were pertinent to me receiving that letter." He jabbed a finger towards the table where the letter still lay. Sherlock plopped back down in his chair. "It's a loop of events, so there must be some sort of time interference here. I don't know how or why, but I intend to find out." John did not even bother to respond, knowing that he would not get any answers.

Sherlock's mind went back to the man and his box that had appeared at the funeral. Both somehow didn't fit, didn't belong there. He connected them to the strange noise he had heard. Connection…?

**A/N2: I just realized that I accidentally changed the spelling of "Rallis" somewhere in the second chapter. Oops. I'll pay more attention. I had a bit of trouble with writing Sherlock today, so tell me if it's too OOC. Thank you sooo much to everyone who reviewed my last chapter! Look forward to another soon. I promise more "timey wimey stuff" (for lack of a better term) in chapters yet to come. Please review! Thanks for reading!**


	5. TARDIS

**A/N: I do not own Sherlock, Doctor Who, or any of their characters.**

As it happened, Ava did come by again. Quite a bit. She and Sherlock started to become almost friends (the level of friendship that the sociopath was capable of). The two sometimes just sat and stared at the symbols on the note together. Sherlock had let Ava see it more closely after a while. He had hoped that she could translate the writing, for it was in fact she who wrote it, but she didn't know any more about it than Sherlock did. However, she still looked distant and nostalgic when she saw the writing, like her mind was somewhere else. She would sometimes take out the watch she always had with her and flip it around in her hands unconsciously.

It almost scared John how similar the two geniuses (which Ava definitely classified as) were. They would finish each other's sentences, or not even finish, knowing the other understood. Sherlock even casually called himself a 'high functioning sociopath' once, and Ava agreed that feelings were distracting. Forget 'opposites attract', Sherlock and Ava were basically the same person and got along astonishingly well.

The interactions had been going on for almost a month when they heard a noise outside. Ava heard it first an hushed the two men. It was a whirring, wheezing, mechanical noise that pulsated and gradually got louder and louder. Both Ava and Sherlock stood with recognition, though Ava had the same slightly confused look about her. Sherlock ran for the door, Ava close at his heels, to investigate.

The two walked outside and saw a big, blue box across the street from the flat. Sherlock was right the first time he saw it at the graveyard: it appeared to be-

"A police telephone box from the nineteen-sixties. Originally made of concrete with only a wooden door, but this one seems to be made entirely of wood." Ava spouted off, finishing Sherlock's thought.

Sherlock, used to this by now, broke a small smile and continued. "It's just a replica though. The windows are the wrong size and it is in perfect condition."

"It was not here before and there are no signs of it being moved here and, judging by it's size, it's too heavy to be picked up. Conclusion:" Ava let him finish.

"It landed here. But there are no signs of wheels or landing gears. No scuffs, burns, and/or scratches from landing. So it just appeared, but how?"

There wasn't even so much as a pause between phrases. The two masters of deduction shared a smile for the joy of having someone that can keep up.

"Wow." Came a voice from the direction of box. Both quickly looked back to see the man in the trench coat from the funeral. He now stood leaning on the side of his police box with his hands shoved in his pockets, staring at them with his ancient eyes. "That, truthfully, was very impressive. And that's coming from me."

Sherlock stepped forward, "And you would be?"

"I'm The Doctor," he stated proudly, shaking each hand in turn. His mouth stretched into a large smile as he spoke.

"I'm Sherlock and this is Ava." Sherlock said dismissively

"So what are you here for?" Ava piped up, also stepping forward to stand next to Sherlock.

"Yes," he agreed. "I saw you before, what do you want?"

"Before?" The Doctor wondered aloud. "I'm here because I had a feeling that something important was here. Something important and...wrong, or…out of place. I just can't put my finger on it." he continued, his smile fading into a confused twist.

"You 'had a feeling'," Ava queried, "That's all you have to go on?"

"Oh, well I'm very intuitive." The Doctor replied with a smug grin.

Sherlock smirked at the strange man's vague response. "So are you going to invite us in, or are you going to make us stand out here forever? It is quite cold."

"Yes, please." Ava agreed. "And I would like to see the inside of your box, Doctor." With that, she walked towards the doors followed by Sherlock and The Doctor.

"This," The Doctor said, pushing past them to unlock the doors, "Is my TARDIS." He pushed them with a flourish and strode up the slope into the vast space inside the comparatively tiny box. "Stands for Time And Relative Dimensions In Space" He said as he turned and rested on the console-like collection of buttons and leavers in the middle of the huge room, smiling and watching the other two walk in.

His grin started to fade when neither said anything. Sherlock said nothing because he had deduced that the box would be bigger on the inside, he didn't feel that anything needed to be said.

Ava, on the other hand, was silent because she felt a huge wave of familiarity and nostalgia wash over her. She had felt the same thing before, but seeing the symbols, hearing the man call himself 'The Doctor', hearing the word 'TARDIS', were nothing in comparison to this. It completely immobilized her. She simply stood just inside the doors, collecting herself, hearing but not listening to the two men talking.

"Well?" The Doctor asked expectantly. "Nothing at all?"

Sherlock walked up the ramp towards him. "Umm it's... Nice." he said awkwardly. He went to inspect the console further. He slowly walked around it, taking in the various knobs, buttons, leavers, etc.

The Doctor frowned and looked around Sherlock to the woman standing at the door. "What do you think, Ava?" he called, waving her over.

Ava's mind was wrenched back to the present upon hearing her name. She slowly made her way up the ramp. "I think it's lovely. How did you get it bigger on the inside?"

The Doctor seemed much more satisfied with this answer. His smile reappeared. "She's dimensionally transcendental, basically another dimension on the inside. It was a key advancement in Time Lord technology."

Ava's ears rang, the only thing she could hear clearly were the words 'Time Lord' echoing over and over in her head. The wave of nostalgia bashed into her again. The repeated feeling began to build up a physical weight on her head.

Sherlock hardly noticed, too intrigued in this new discovery. "So is that what you are, then?" He asked The Doctor. "A 'Time Lord'?" 

"I'm sorry?" he called from the other side of the console. 

"Your TARDIS, it's obviously alien technology. And, though you appear to be human, it is very unlikely that a human would be able to get their hands on, much less know how to use, something like this. So, are you a 'Time Lord'?" 

"Yes." The Doctor said, suddenly somber. "The last one, I should think." He looked first at his feet, then at the distant ceiling, then shook his head and looked quickly back to Sherlock. 

"So I've basically just told you that I'm an alien with a box that's bigger on the inside and can travel through time and space." He suddenly snapped back to his cheery attitude and started to run around the console. "And that hasn't even shaken a reaction out of you. So what I would do in this kind of situation is give a demonstration!"

The Doctor hopped into action. He whirled around the controls like a madman, flipping this switch and pushing that button. He skidded to a halt in front of Sherlock, a huge maniac grin on his face. "You may want to hold onto something." With that, he slammed his hand down on one last button and the room gave a great jolt, sending the inexperienced flyers to the ground. The large cylinder jutting out of the center of the floor moved up and down and a much louder and clearer version of the mechanical wheezing rang through the space.

The TARDIS continued to rumble and wheeze, but had calmed enough after a few seconds for Sherlock and Ava to regain balance.

Sherlock walked over to see what The Doctor was doing. He now wore a pair of glasses and stared at a screen. Sherlock noticed several sticky notes stuck on the sides of the monitor, and on them notes in the same complicated, circular language. He took his own note from his jacket, holding it up so that he could see it but The Doctor couldn't. the symbols were different, but had the same kind of look to them: mechanical looking circular shapes inside other larger circles. It was now obvious to Sherlock who the note was meant for. _Not yet_, he thought. She wrote it in the car, so The Doctor must not be meant to see it yet.

Meanwhile, the noise of the moving TARDIS, now that she heard it up close, hit Ava so hard it made her dizzy. She carefully made her way to the black leather chair by the railing and took a seat. She took out her small fob watch and staring at it, but not quite seeing it. Her attention was pulled back slightly back by The Doctor asking if she was okay. 

"Ava?" The Doctor asked, worried. She no longer looked like the confident woman that he had seen outside. She looked scared and confused. He noticed the watch she had in her lap. The way she looked at it. Oh yes, he knew that look. He had felt that look before, knew the piled up emotions behind it. The Doctor went to sit next to her. 

"Ava, I can't help but notice, you have a fob watch." She looked up at him and nodded. "May I see?" he asked gently, holding out a hand. She looked down at her watch then up at the Doctor's face, then down again, eyes following the watch as she lowered it into his hand. Sherlock came over and stood in front of them and folded his arms, carefully measuring Ava's expression.

The Doctor turned the watch around, revealing a great amount of the strange writing engraved in the silver surface. Sherlock lifted an eyebrow, intrigued. Those symbols seemed to surround Ava, but she had no idea what they were. 

"What is it, Doctor?" Ava asked as he set the watch back onto her lap. 

"It's important and out of place." he said, somber again. "I'm sorry, but I can't tell you. You will have to open it only when the time is right. You'll know." He gave her a sad smile. The TARDIS landed with a hollow clunk that reverberated through the vast space. The Doctor sprung up out of the chair, suddenly bright again. Ava shook the uncomfortable weight out of her head and, now her usual, more confident self, stood to look expectantly at The Doctor.

"Here we are!" He strode to the doors and turned to smile at the curious two.

"And where is 'here' exactly?" Sherlock questioned, walking down the ramp towards him.

"This, is the beautiful blue planet," The Doctor turned to open the doors while announcing, "Metabelius…..three." He stopped short stepping out into what should have been a whole new world, his excited announcement fading into a slow whisper. He spun around and ran back up the ramp to the console, the doors closing behind him. He glanced at the screen and mumbled, "twenty-first century London." He turned back to the two geniuses, "This is about a month earlier than where we left, and about a mile away."

**A/N: Ooo, can anyone guess who Ava is? I know I kind of stopped short this chapter, but if I kept going it would be too long. Thank you so much to every wonderful reviewer! Keep the reviews coming and I'll keep the chapters coming! Thanks for reading!**


	6. Loss

**A/N: I do not own Sherlock, Doctor Who, or any of their characters.**

"So much for time and space." Sherlock said sarcastically. 

"No no no no no. I can fix it!" The Doctor said quickly, again running around the controls. Another bumpy, noisy minute later, the TARDIS came to a halt. The Doctor ran back past Sherlock and Ava, who were again pulling themselves off the ground.

He threw open the doors, leant out, looked around a bit, then came back in, closing the doors behind him. He ran back up the ramp.

The Doctor glanced at the screen again and groaned. He ran back around the controls. He flipped a few more switches and ended up with a loud, high-pitched, unpleasant ringing. The Doctor took out a small hammer hanging on a hook and hit the console with it. Sherlock thought he heard the time traveler chiding the machine quietly.

The Doctor sighed and spun back to look at the two. "Two months." he said, sounding disappointed. "Two months in your past and _still_ in London." 

"Can't you just try again?" Ava asked. 

"She won't budge. I guess she wants us to be here." he said quietly, more to himself than to answer Ava. 

"'She' wants us here?" Sherlock asked, intrigued. "Who's 'she'?"

The Doctor hopped back up, again energetic. "The TARDIS!" he replied, walking over to the detective. "She's got a mind of her own, and she wants us here!" He stopped in front of the doors, grinning widely at them. "Let's go see why!" With that he pushed the doors open with a wide gesture telling the other two to follow him. He led them out into a long alleyway, several metres away from a busy street.

Sherlock knew why they were there. It was because two months in his past, Ava had wrote a note to him and a few weeks later, she died in a car crash. He knew that it would have to happen, he just hadn't allowed himself to think about it until now.

Ava also knew. She noticed that Sherlock had recognized her that first day. She had collected that he was not one for meeting new people, much less making friends. She saw him staring at her when he thought she wasn't looking, as if trying to find out how she was there. And she _certainly_ did not miss the open envelope on the coffee table that first day. The letter written to Sherlock Holmes in her handwriting, her favorite dark green pen. She knew what she had to do.

Ava held back in the alleyway. She took the watch out again and felt tears start to well up in her eyes. Sherlock noticed, walking back to her as the Doctor continued around the corner obliviously talking to himself. 

"Ava? Are you alright?" he asked, concerned (though concern was an astonishingly rare emotion for said sociopath). She didn't answer, just staring at the watch that she always had but never noticed. 

"What is it?" Sherlock prodded, trying to read her expression through the curtain of ginger curls.

Ava looked up at him slowly, vibrant green eyes full of sad understanding. "You have to leave me here." she said simply. 

"Yes." he replied, seeing that she had pieced it together like he knew she would.

She swallowed and looked back down to the watch, hiding her face and slightly shaking her head. "You knew you would have to leave me here."

"Yes, I did."

Ava chuckled quietly, "This whole time, you knew how I was going to die." Sherlock saw a tear fall onto the polished silver surface.

He lowered his head and clasped his hands behind his back, slightly ashamed. To his surprise, Ava quickly stepped forward and hugged him.

"Goodbye Sherlock Holmes, and thank you. I will never forget you." She whispered. There was a pause while Sherlock got over the surprise and awkwardly hugged her back.

"And you, Ava." He said, just as quietly.

Ava burrowed her face in his shoulder, tears falling onto his long coat, and murmured one last, barely audible "I love you" and briskly walked away, never to be seen again.

Sherlock stood motionless where she had left him, truly awestruck for the first time in his life. He took several seconds to collect himself. "Doctor!" he called around the corner, the man couldn't have gotten far.

Having noticed the lack of responses and/or questions coming from Sherlock and Ava, the Doctor had already begun to make his way back to the alleyway, running the rest of the way upon hearing Sherlock call him.

"What is it?" He ran around the corner. "Where's Ava?" He asked, getting even more worried.

"She's gone, Doctor." Sherlock responded, solemnly. "She had to go." He turned and walked back into the TARDIS.

"What?" The Doctor asked, harsh and serious. He followed the detective in and ran ahead so that he was facing Sherlock. "She _can't. _Her past self is here, she can't run into hers-"

"I know that." Sherlock shot back, equally as stern. "And she knows that. She'll be careful. She had to go."

"Why?"

"She has to go and die." He said, cutting off the Doctor's response by lifting a hand. "She wrote me a letter telling me to go to her funeral so that I would recognize her." He explained. "You and I both only met her because she died. I'm not any happier about it than you, but it has to happen."

The Doctor nodded, understanding. He walked over to the black leather chair and heavily sat in it. "I just hoped that I wouldn't be alone anymore." He admitted.

"What do you mean?" Sherlock asked.

He leant forward to look at Sherlock, still standing on the ramp. "The Time Lords, they're all gone. Or at least I thought they were. But that watch that Ava had, it gave me hope." He slumped back into his chair. "That watch meant that she was a surviving Time Lady."

Sherlock raised his eyebrows in surprise, walking up the ramp. "But she didn't know, did she?"

"No, she turned herself Human. She must have been running. Only logical, I'm still running." The Doctor answered sadly.

"Running from what?" Sherlock asked.

"Nothing," the Doctor dismissed, though it was clearly not 'nothing'.

Sherlock remembered the note, the scrap of paper with the symbols that Sherlock had seen in the Doctor's own handwriting. He pulled it out of his jacket pocket. "Doctor, she wrote you a note." He said, holding the paper out for the Doctor.

He got up and took the note. Without a word, he unfolded the paper, glanced at it, then folded it again and put it into his own jacket. He walked, slowly this time, around the controls in the center of the room. He turned a few knobs and pulled a few leavers and the TARDIS obediently jolted into action, whirring and wheezing but traveling smoothly. They both stood in silence until the time machine landed with a hollow clunk.

"Where are we now?" Sherlock asked, looking to the door.

"221B Baker Street. We've been gone for five minutes."

"I see." Sherlock responded, walking to the doors. He stopped in front of the exit and turned to face the Doctor one last time. "Thank you, Doctor." He said, and turned to leave the TARDIS for the last time.

Once outside, Sherlock heard the now muffled mechanical wheezing. He looked back to watch the police box fade and finally disappear, as if it were never there.

"So, what was it?" John asked once Sherlock opened the door.

"Nothing," the detective dismissed, though it was clearly not 'nothing'.

"Where's Ava?" the doctor queried.

"She had to go." Sherlock replied, taking the time to hang up his coat and scarf.

"So did you figure it out? How was she here?"

Sherlock smirked and lied, "I guess we'll never know."

**A/N2: Emotional chapter. There always has to be one. Thanks to everyone who reviewed! I hope you're enjoying it so far! Please review and thank you all for reading!**


	7. Memory

**A/N: Thank you so much to everyone who reviewed my story so far! Note: I do not own Sherlock, Doctor Who, or any of their characters.**

Ava lived in a flat those few weeks after leaving Sherlock and the Doctor. She had been careful; recalling where and when she had been the first time around, it would be bad if she ran into herself. She also avoided anyone who may recognize her, which proved not to be to difficult seeing as her past self hadn't lived in London too long either.

The second day Ava was there, she wrote the letter to Sherlock. She knew that he would have to recognize her when he met her on the street that first day. This meant that Sherlock would have to see her dead. A bit unpleasant, but when he did, he wouldn't know her. Ava carefully wrote the note with her favorite dark green pen and sealed it in an envelope, neatly printing his name on the front. She folded the note and put it in her purse, knowing that Sherlock would get it eventually.

Ava usually spent her days walking around town, carefully avoiding where she had been, when it was nice out or staring out the window of her three story flat when it rained. Occasionally she drove around the large city, taking it upon herself to see the whole of this beautiful city she hadn't appreciated nearly enough before. She explored every urban highway and abandoned back street the same, taking in the whole character of the metropolis in her last weeks.

Ava found that she had quite a bit of time to think. She thought about mortality a lot. She tried to justify the fact that she would be dying so young by telling herself that she had had a full life. But she was lying to herself. She could not remember a single detail of her life before she had moved to London. She could remember places and times, but not a single specific.

Ava was often plagued with vivid dreams. She imagined both amazing landscapes and horrifying monsters. She dreamed that she knew those places and creatures, watched them as an unassuming observer.

She thought about that Doctor and his odd blue box that defied all laws of physics. She pondered the Doctor's words when he saw the fob watch. They ran over and over in her head as she tried to decipher their meaning.

Ava sometimes sat in her empty flat just staring at the watch. She constantly forced herself to focus on it and how it made her feel. She felt the nostalgia more and more often now, almost all of the time. Ava thought about opening the watch several times, curious as to what about it was so wrong, but some voice in the back of her mind told her it was not yet time.

One cold, rainy day, Ava decided to go on one of her drives to explore London and after a while, found herself in a particularly empty side street. She drove through quickly, taking in the dilapidated buildings and the rubbish that covered the filthy, unused walks.

Ava's thoughts went back to the watch as she drove down the long, winding street. She made the mistake of glancing down at the polished silver circle sitting in the cup holder next to her.

This was a mistake because what she had intended to be a glance turned into an engrossed stare. It finally pulled all of her attention towards it, rather than away. She took in the circular shapes engraved into the front, noticing them before but never quite seeing them. She was again overtaken by the nauseating familiarity. Some loud, disembodied voice in her head pushed itself forward and yelled "IT'S TIME! NOW!"

Ava glanced briefly at the barren stretch of road in front of her before snatching up the fob watch. She held it in her hand for a second and finally opened it.

The watch snapped open with a burst of glowing, golden mist. The light washed over Ava and all time stopped. A picture of a beautiful landscape appeared in her mind: a shimmering city, encased in a huge glass dome. Above, two orange suns hung in the sky, giving everything a golden glow. Wind swept through the deep red grass that covered the slopes behind the mighty city. The shining world. The citadel of the Time Lords. Her home. Gallifrey.

Ava finally remembered. She remembered every single day of her 2000 years of life and felt the knowledge of all of that time bearing down on her with a comfortable weight. She heard the familiar _thud-thud-thud-thud_ of her two hearts racing. It all made sense now, the Doctor, the TARDIS, the watch, all of which she felt like she knew. Those vivid dreams were no longer her imagination, they were her memories.

Then she knew the Doctor. She remembered who he was, remembered that she had thought he was dead. She knew that he probably thought the same of her. It was then that she realized that her dear Doctor would never know that she was alive all those years.

Ava remembered that note Sherlock had shown her, the complicated circles. She summoned up a picture from her immaculate memory and finally understood the writing. Specifically, her signature at the bottom.

Ava dug through her purse for a pen and paper, glancing every now and then back up at the stretch of road. She found a small pad of paper and her green pen. She ripped out a single piece of paper and attempted to write out a quick note with her dark green pen. With a few scribbles in the corner, she realized that the pen was out of ink.

Ava huffed and dug a pencil out of her purse and quickly scribbled a note to the Doctor, knowing that Sherlock would eventually find out who it was for. She closed the note in the window to insure that it would be found.

She felt tears again welling up in her emerald eyes for her inevitable fate, saying a final mental goodbye to those she loved. She focused again on the road, mind finally being pulled back to her speeding car.

She looked up and let one, single, crystalline tear fall. She saw an old abandoned convenience store on the corner of the only sharp turn on the winding road. Ava braced herself for the collision.

Everything went black with a single flash of pain as she was thrown into the steering wheel, crushing her chest and stopping her hearts. There ended the life of the last surviving Time Lady of Gallifrey.

**A/N2: Sorry its shorter and possibly a bit depressing, but I personally like this chapter. Look forward to the eighth and final chapter soon. Please review and as always, thank you all for reading!**


	8. Endings

**A/N: I do not own Doctor Who, Sherlock, or any of their characters.**

The Doctor let the TARDIS drift through empty space so that he could read the letter from the Time Lady he had assumed he didn't know. He dug the paper out of his impossibly deep jacket pocket and held it in front of him.

It was written in Circular Gallifreyan. The complex circles and lines that formed words. He read the letter.

_My Dear Doctor,  
>I am so sorry that I didn't get the chance to speak to you again, and I'm afraid you will also never get that chance. I've used up my lives and will not be able to regenerate again. Do not weep for me, I lived a full 2000 years. Funny, you never really realize how short life is until you reach the end of it. Thank you, Doctor, for giving me one last, if small, adventure. Never forget me and continue the legend of our world.<br>Avashta_

The Doctor's mouth fell slightly open and eyebrows disappeared into his untidy hair upon reading her full name at the bottom of the letter. A name he hadn't heard or seen since he left Gallifrey, never to look back. His surprise slowly melted into sadness, knowing that he would never see her again. If he was meant to, she would have remembered it. Some things, he thought, must happen.

The Doctor slowly wandered around the console; programming the TARDIS to the one place he could see the Time Lady again. The time machine gave a small jolt and landed quickly with a satisfactory clunk.

The Doctor stood behind the doors for a second, taking a deep breath to prepare himself. He pulled one door open and stepped out into a graveyard, mentally thanking the old girl for landing in just the right time and place.

The Doctor and his TARDIS now stood beneath a thick, low tree that concealed the time machine nicely. The Doctor stepped a little farther forward so that he could see the casket in front of the deep grave. Sherlock stood looking down at it as if analyzing the body inside instead of mourning the wonderful person it used to be. He obviously hasn't met her yet, thought the Doctor. The other man spun around when he heard the landing and scanned over the area of the TARDIS a few times before actually seeing it, being fooled by her small perception filter.

He took his eyes off the detective and looked at the Time Lady resting inside the shining black coffin. She looked peaceful enough, but the Doctor could hardly believe that she was gone.

The Doctor noticed out of the corner of his eye Sherlock staring at him and his TARDIS, but didn't take his eyes off of Avashta. The Doctor waited for Sherlock to walk away, which didn't take too long, before approaching the coffin. He walked slowly forward, coat billowing behind him.

Only then, when he was standing at the edge of Avashta's open grave, did the full force of her death hit him. When he knew her, she had been so bright, so positive. Now, the whole universe felt slightly gloomier without her, mourning her with the fittingly heavy, gray sky. The Doctor knew he was now truly alone, though he had thought this from the beginning. This one small, human resting place nearly broke him. It brought back memories of his family and friends all dying in the war that could only end in destruction.

The Doctor stood there in mourning until he could stand it no longer. The Time Lord stepped back from the grave and took one, final, long look at his dear sister that he seldom saw and probably never would again.

**A/N2: This is the end of A Mystery Of Time. Thank you so much to everyone who read, reviewed, favorited, and/or followed! Please leave a review telling me what you thought, even if you don't have much to say. Thank you all so so so much for reading!**

**Thank you and goodbye,**

**BAngel**


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